Patent attributes
A metering valve is provided for a pressurised container containing a pharmaceutical formulation. The valve has a stem with a central flange and a hollow open end with a side port. The stem slides in a body having larger and smaller diameter portions, and being closed off by a seal against which the flange rests in an inoperative position. A second seal is located around the stem on the opposite side of the flange and trapped by a spring which urges the stem into its inoperative position. When the stem is depressed, the inner seal forms a sliding seal with the smaller diameter portion of the body to define a metering chamber filled with the pharmaceutical formulation. Continued depression opens the side hole to allow the contents of the metering chamber to be dispensed.
